Does anyone know of a battery powered ZigBee or Z-wave (EU) temperature sensor that can manage ~120 C?
Alternative, the temperature probe could be external on a wire. It never get that hot down on floor level.
I have looked in our (Sweden) stores but haven't found any that seems to work.
A range of the Fibaro devices allow for an external temperature probe (a DS18B20, you can get from them or other sources). These can be protected against the humidity of the sauna, with the main sensor itself being outside of it. One idea might be to use their contact sensor on the outside. That way you know if someone leaves the door open.
Interesting. I don't think the main unit needs protection since it doesn't gets to humid down by the floor.
Thank you!
Probably true, as long as the main unit would not be placed near the stones for when water is added. 
Hmm... Looked at the Fibaro page for the Door/Windows sensor and... Temperature measuring
range: 0-60°C (32-140°F).
60°C is unfortunately not high enough.
Ah... bummer. That must be a limitation of the Fibaro itself because the DS18B20 technical specs are -55 to 125°C (-67°F to +257°F).
It's probably a dead end but I would email Fibaro support to verify the FGK-10x really won't read to 120°C.
If by some chance it does work, I would put the unit outside the Sauna and get a sealed DS18B30 Sensor. It may not be as "steamy" down at the floor but its very humid.
John
If putting the unit outside the sauna with a probe inside is an option and since you already use Tasmota, you could attach a DS18B20 sealed sensor to a Tasmota-based device and use that. Or even a PT100 or PT1000, though those are a bit harder to get setup properly.
Once configured with the right template setting in Tasmota, my driver will detect it as a temperature sensor and create the right child device.
I agree if external power is an option. I would stay with the DS18B20 a I believe they will be better for rejecting electronic interference, and the ESP8266 has a horrible A/D input.
You can purchase the DS12B20 in a sealed sheath with a long wire (length =?) all ready to work in moist environments.
If you go down this road take a look at Hubduino by @ogiewon. I believe all the software you need is in this package all the way from the DS18B20 ---> Hubitat (driver) all complete and ready to run.
True, when I've used PT100 and PT1000 sensors I've added a separate A/D converter. The added precision from these sensors would not be needed in a sauna... 
With DS18B20 you could even put a couple of them together on the same wire (they use the 1-wire protocol) if you wanted temp outside as well as inside the sauna.
That is the route if you want to compile the firmware on your own, if you don't want to Tasmota works well for this as well, and you already use it so know how.
EDIT: One thing, for a sauna I'd want a humidity sensor as well...
I'm not familiar with Tasmota but it sounds kinda like a general purpose system (not sure system is the right word)
I wonder if Tasmota will work with Hubduino? I'm assuming Tasmota doesn't have a matching Hubitat app.
That is the route if you want to compile the firmware on your own
I believe the Hubduino code is ready to go. I used the Arduino IDE to compile and download.
One thing, for a sauna I'd want a humidity sensor as well...
My guess it would be saturated at 98% or whatever the max is.
Tasmota is a firmware that runs on ESP8266-based devices. It definitely has a matching driver and app, one which would even auto-detect the number of sensors you put in a device. I've tested it with 8 sensors in one device, all showed up as separate child devices without any extra configuration. No compiling of your own firmware, no editing and choosing drivers. But yes, Hubduino has other uses, like for motors and for those that want special features and settings not available in Tasmota.
Code is mostly ready, just some configuration depending on use, but you do have to compile it.
When in use, yes, but not before or after. I'd monitor the after values to make sure that ventilation is right after use.
Thanks for bringing up Tasmota, I'll have to look into it
I'm a bit biased though, I wrote the app and driver for HE and made the latest version of the modified Tasmota firmware for use with HE.
Cool. I just browsed the website. It wasn't obvious how the board communicates with Hubitat.
Is it Tasmota board --> router ---> Hubitat? Or does it go "outside"?
Thanks guys but I “need” a battery powered device that can be mounted inside the sauna.
Will keep looking and keep an eye in this thread for further suggestions.
How about one meant for BBQ? MEATER+:
There are also industrial lora-based sensors...
I have a Xiaomi Aqara temp/Humidity sensor in my Sauna.
It's main use is so that Echo Speaks alerts me that the Sauna is up to temperature and ready for me to go get cooked..... Once I'm in there there's the traditional temperature and humidity dials that tells me at a glance how it's doing.
Simon
Thats exactly what I want to do. I will have a look at the Aqara sensor you mentioned. Thanks!
EDIT The spec for that sensor says up to +50C (122F). Does you manage to measure higher temperatures?
My Sauna is usually running at 75 to 80C - I get it to alert me when it gets close to 70 and it's usually nearer 75 by the time I'm ready.
Download the Hubitat app
